In a stunning move, Google executive Marissa Mayer has stepped down and been named CEO at Yahoo.

The 37-year-old will be Yahoo’s fifth CEO in the past five years as the Silicon Valley company has struggled with layoffs and internal problems.

Mayer will replace Ross Levinsohn, who has served as interim CEO following the flap over former top exec Scott Thompson and misinformation on his biography.

In a statement from Yahoo, Mayer said “I am honored and delighted to lead Yahoo, one of the internet’s premier destinations for more than 700 million users. I look forward to working with the company’s dedicated employees to bring innovative products, content, and personalized experiences to users and advertisers all around the world.”

Mayer had spent 13 years with Google, coming onboard in 1999 and helping the tech giant become the leader in the search engine field.

No word yet on who will replace Mayer at Google, but certainly some big shoes to fill.